Television writer-producer
Sam Simon, who co-created
"The Simpsons," is facing down a terminal colon cancer diagnosis by spending his vast fortune on feeding the hungry and animal rights.

Simon left FOX's iconic animated series in 1993, though he kept a highly lucrative executive producer title, and became known throughout Hollywood for his philanthropy. He founded the Malibu-based Sam Simon Foundation (worth $23 million as of 2011) that rescues stray dogs and feeds the hungry with vegan foods. He's also worked with PETA, Save the Children and the Sea Shepherd Conservation Society, as well as turning a Malibu home into a canine rescue center that saves dogs from kill shelters and trains them to be companions for the deaf.

On a May 16 "WTF With Marc Maron" podcast, Simon confirmed that he had been given a prognosis of three to six months to live and vowed to donate nearly off of his "Simpsons" royalties -- which he says earns him "tens of millions" annually -- to charity.

Speaking with
THR, Simon explains why he's determined to give all he can give in the time he has left. "One thing is, I get pleasure from it. I love it. I don't feel like it is an obligation," he says. "One of the things about animal rights, which is not the only thing that I care about in this world, is that your money can bring success. I see results. There is stuff happening, really good stuff, every week. I'm not sure you get that with a lot of disease charities. If you were donating to environmental causes for the past 20 years, do you think your money is doing anything?"

As for the kind of change Simon would like to see in the world, he says, "I want medical experiments on animals stopped. They don't do anything, and they don't work. Veganism is an answer for almost every problem facing the world in terms of hunger and climate change. It helps people's health. Meat is the biggest greenhouse gas producer. There's also the cruelty and suffering aspect. When people do meatless Mondays, and when people adopt instead of buying a dog, that's a PETA victory."

Simon admits that cancer hasn't affected his sense of humor, but it has changed the way he looks at television: "There's some stuff on TV that I'm like, 'With the time I have left, do I really want to watch 'Wipeout'?' But I have a problem when it comes to watching 'Big Brother.' I got my shows. TV for a cancer patient."